FLOOD06285 - Laserfiche WebLink

Home Browse Search

3 period has not yet started. Where this freeboard criteria has not been met, the onus for demonstrating that protection from the one percent chance flood does exist, with a lesser freeboard, viII be on the levee owner. As dLacussed above, this viII be a difficult analytical task which must address all the uncertainties involved in establishing flood discharges, and the structural atability of the levee system itself. A report documenting such analyses must be aubmitted to, and approved by, FIA before such a levee will be credited. Inspection and Evaluation Prior to any levee system receiving credit on any future map issued by FIA, the contractor responsible for the production or revision of that map will be required to determine that the minimum design requirements itemized above have been met. In addition, a field inspection or suitable alternative, will be required to verify that the levee appears structurally sound and adequately .maintained. A certification froQ a Federal or state agency, or a registered professional engineer that the levee meets the minimuQ design criteria above and that it appears, upon visual inspection, to be structually sound and adequately maintained may be utilized in lieu of a site specific inspection by the contractor. Levees with obvious structural defects or obvious lack of maintenance will not be credited by FlA. Human Intervention and Operation of Closures In general, FIA viII not recosnize human intervention (e.g. capping ~f levees by sandbagging, earth-fill, flashboards, etc.) for the purpose of increasing a levee's design level of protection during an imminent flood situation. The levee must be designed and maintained to provide adequate IOQ-year protection without human aupplementation. Human intervention will only be accepted for the operation of closure structures (e.g. gates, stop logs, etc.). in a levee system designed to provide at least lOa-year flood protection, including adequate freeboard as described above. FIA will recognize levees with closures only under the following conditions: 1. The levee system was designed with the closure to be an integral part of the system during operation. Sandbagging of openings would not be sufficient. 2. The levee system was designed to require human operation of closures or human backup is provided for automatic systees. 3. Sufficient flood warning time exists for the operation of all closure structures, including necessary sealing, before flood waters reach the base of the closure. 4. Operation and maintenance of closure structures are responsibilities mandated by local ordinance. 5. A formal operation plan addressing closure operation and including specific assignments of responsibility is available and capable of being implemented.